Conveyor system with distributed article manipulation

ABSTRACT

A system and method for manipulating articles includes providing a bed having at least one conveying surface. The conveying surface is adapted to move articles in a direction of conveyance from an upstream end to a downstream end of the bed. At least one sensor is provided to determine the position of any articles on the bed. Selected articles are moved in the direction of conveyance at a speed that is generally higher than articles traveling on the bed that have yet to be manipulated and the articles are selectively rotated.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from U.S. provisional patentapplication Serial No. 60/422,028, filed on Oct. 29, 2002, thedisclosure of which is hereby incorporated herein by reference in itsentirety.

BACKGROUND OF INVENTION

[0002] The present invention relates to conveyors, and more particularlyto conveyors that manipulate articles. The invention may be applied inmany ways, including by way of example, to separate batches of parcelsby releasing parcels one at a time. Another application is to manipulatea stream of articles by delivering the articles one at a time withgenerally controlled gaps between the articles. The articles may also bealigned, such as lengthwise.

[0003] Conveyors—such as belt conveyors, roller conveyors, and othertypes of conveyors—are in widespread use today for moving packages,parcels, mail, boxes, and other articles from one place to another. Inmany situations the articles that are to be carried by the conveyor areinitially placed on a conveyor in a manner that is not conducive tobeing transported and processed by the conveyor system. Typically, theconveyor system is set up to optimally transport articles when they arearranged in a single-file line. In many situations, articles enter aconveyor system on conveyors that are sufficiently wide to accommodatemultiple articles positioned side-by-side. In order to effectivelyprocess these side-by-side articles, it is desirable to manipulate themsuch that they are no longer arranged side-by-side, but rather in asingle-file line. It may also be desirable to provide controlled gapsbetween the articles and to orient the articles in a particular manner,such as lengthwise.

[0004] In the past, several different types of article manipulators havebeen used, but these all contain features that have room forimprovement. For example, PCT Application Serial No. PCT/US00/11370(Publication No. WO 01/74693) discloses a hold and release singulatorfor manipulating items being transported. The hold and releasesingulator operates in a batch like fashion. In other words, groups ofarticles are transported onto the singulator, then stopped, and thenindividually caused to exit the singulator one at a time. After all ofthe articles have exited the singulator, another batch of articles ismoved onto the singulator and the process is repeated. This method mayproduce an uneven flow of articles exiting the singulator. Further, abatch type manipulation process may not manipulate items as fast as acontinuous process.

[0005] A continuous type of manipulation process is disclosed inEuropean patent publication EP 0 979 788 82 (application number99250264.1). However, not all items that enter the singulator of thispatent will necessarily be manipulated during their first transport overthe manipulation bed. The manipulation device disclosed in this patentincludes a return section 70 in which non-manipulated items arere-circulated through the singulator. The re-circulation of these itemsis generally inefficient. Further, additional floor space must beprovided to accommodate the re-circulation conveyors. Oftentimes factoryfloor space is at a premium and the use of additional space is desirablyavoided.

[0006] PCT patent application serial no. PCT/US01/13556 (Publication No.WO 01/83339) discloses another existing type of article singulator.While the application discloses several different embodiments of anarticle singulator, none of these embodiments disclose a singulatorwhich rotates articles. In addition to manipulating articles into asingle file line, it is often desirable to rotate the articles such thattheir longitudinal axis is generally parallel to the longitudinal axisof the conveyor. The articles that enter a singulator are customarilyoriented at all different angles. When a singulator is used, such asthat disclosed in PCT application PCT/US01/13556, the orientation of thearticles are not altered using the singulator. The articles thereforemust be processed having skewed angular orientations, or additionalmeans must be provided to rotate the articles to a desired orientation.

[0007] In light of the foregoing disadvantages with several of the priorart singulators, the desire can be seen for an improved singulator thatovercomes these and other disadvantages.

SUMMARY OF INVENTION

[0008] Accordingly, the present invention provides an improveddistributed manipulation system that overcomes many of the problemsassociated with the prior art. Specifically, the distributedmanipulation system of the present invention takes up relatively littlefloor space, processes articles in a rapid manner, does not requirerecirculation of the items, is relatively quiet, and may process up to6,000 or more articles per hour wherein the articles may have an averagelength of about 20 inches. The distributed manipulation system,according to the invention, utilizes a significant number of individualactuators to achieve exceptional dexterity.

[0009] A system for manipulating articles generally traveling in adirection of conveyance, according to an aspect of the invention,includes a bed made up of a plurality of conveyor groups, each of theconveyor groups being aligned with each other in the direction ofconveyance and each of the conveyor groups made up of a plurality ofindividual conveyors positioned side-by-side in a direction transverseto the direction of conveyance. The conveyors are adapted to at leastpartially support articles traveling thereon and to move the articles inthe direction of conveyance. At least one sensor is provided that isadapted to determine the position of the articles traveling over theplurality of conveyor groups. A controller is provided in communicationwith the at least one sensor and the conveyors. The controller isadapted to manipulate articles traveling on the manipulation bed bycontrolling the speed of the conveyors. The controller is furtheradapted to rotate an article positioned on the manipulation bed bycontrolling the speed of selected ones of the conveyors underneath thearticle such that at least the first one of the selected ones of theconveyors has a different speed than a second one of the selectedconveyors.

[0010] A method of manipulating articles, according to another aspect ofthe invention, includes providing a bed having at least one conveyingsurface adapted to move articles in the direction of conveyance from anupstream end to a downstream end of the bed. The method further includesproviding at least one sensor and using the at least one sensor todetermine the position of any articles on the bed during at least onemoment in time. The method further includes selecting an article on thebed to be manipulated, determining whether the selected article is to belocated, and moving the selected article in the direction of conveyanceat a speed generally higher than articles traveling on the bed that haveyet to be manipulated. If the article is to be rotated, the selectedarticle is rotated.

[0011] A system for manipulating articles generally traveling in adirection of conveyance, according to another aspect of the invention,includes a bed having at least one conveying surface adapted to movearticles in a direction of conveyance from an upstream end to adownstream end of the bed. At least one sensor is provided that isadapted to determine the position of the articles traveling on the bed.A controller is provided that is in communication with the at least onesensor and the bed. The controller is adapted to manipulate articlestraveling on the bed by controlling the speed of the conveying surface.The controller is further adapted to determine if two articles havingoverlapping alignment in a traverse direction on the bed are on oppositesides of a dividing line extending in the direction of conveyance. Thetransverse direction is that which is extending in a directiontransverse to the direction of conveyance. The controller is adapted tocause the two articles to exit a downstream end of the bed during atleast one coincident moment in time if the two articles are on oppositesides of the dividing line.

[0012] A method of manipulating articles, according to another aspect ofthe invention, includes providing a bed having at least one conveyingsurface adapted to move articles in the direction of conveyance from anupstream end to a downstream end of the bed. The method further includesproviding at least one sensor and using the sensor to determine theposition of any articles on the bed during at least one moment in time.The method further includes determining whether two articles on the bedhave overlapping alignment in a transverse direction and whether the twoarticles are on opposite sides of a dividing line. The transversedirection is that which extends in a direction transverse to thedirection of conveyance. The dividing line extends in the direction ofconveyance. If the two articles are on opposite sides of the dividingline and have overlapping transverse alignment, the method providesmoving the two articles such that they exit a downstream end of the bedduring at least one coincident moment in time.

[0013] A system for manipulating articles generally traveling in adirection of conveyance, according to another aspect of the invention,includes a bed comprising a plurality of conveyor groups, the conveyorgroups being generally aligned with each other in the direction ofconveyance. Each of the conveyor groups consists of a plurality ofindividual conveyors positioned side-by-side in a direction transverseto the direction of conveyance. The conveyors are adapted to at leastpartially support articles traveling thereon and to move the articles inthe direction of conveyance. At least one sensor is provided that isadapted to determine the position of the articles traveling over theplurality of conveyor groups. A controller is in communication with theat least one sensor and the conveyors. The controller is adapted tomanipulated articles traveling on the bed by controlling the speed ofthe conveyors. The controller is further adapted to be able to controlthe speed of the conveyors at more than two different non-zero speeds.

[0014] As noted above, the various embodiments of the present inventionprovide a quiet, fast, compact, distributed manipulation system thatuses no re-circulation. These and other benefits of the presentinvention will be apparent to one of ordinary skill in the art uponreview of the following specification and accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0015]FIG. 1 is a plan view of an article manipulation system accordingto one embodiment of the present invention;

[0016]FIG. 1A is a side, elevational view of the article manipulationsystem of FIG. 1;

[0017]FIG. 2A is a perspective view of one of two individual conveyorsin a conveyor unit that may be used in the manipulation bed of FIGS. 1and 1A;

[0018]FIG. 2B is a perspective view of the other of the two individualconveyors in the conveyor unit shown in FIG. 2A;

[0019]FIG. 3 is a plan view of a second embodiment of an articlemanipulation system according to the present invention;

[0020]FIG. 3A is a plan view of diverter/merge conveyor of FIG. 3;

[0021]FIG. 4 is a plan view of a manipulation bed and adjacent conveyorsat a first moment in time;

[0022]FIG. 5 is a plan view of the conveyors of FIG. 4 at a secondmoment in time;

[0023]FIG. 6 is a plan view of the conveyors of FIG. 4 at a third momentin time;

[0024]FIG. 7 is a plan view of the conveyors of FIG. 4 at a fourthmoment in time;

[0025]FIG. 8 is a plan view of the conveyors of FIG. 4 at a fifth momentin time;

[0026]FIG. 9 is a plan view of the conveyors of FIG. 4 at a sixth momentin time;

[0027]FIG. 10 is a plan view of the conveyors of FIG. 4 at a seventhmoment in time;

[0028]FIG. 11 is a plan view of an article manipulation system thatincorporates the elements of the system of FIG. 3;

[0029]FIG. 12 is a plan view of a manipulation bed and adjacentconveyors that may be utilized in conjunction with the conveying systemof FIG. 11, shown at a first moment in time;

[0030]FIG. 13 is a plan view of the conveyors of FIG. 12 shown at asecond moment in time;

[0031]FIG. 14 is a plan view of the conveyors of FIG. 12 shown at athird moment in time;

[0032]FIG. 15 is a plan view of the conveyors of FIG. 12 shown at afourth moment in time;

[0033]FIG. 16 is a plan view of the conveyors of FIG. 12 shown at afifth moment in time;

[0034]FIG. 17 is a plan view of the conveyors of FIG. 12 shown at asixth moment in time;

[0035]FIG. 18 is a plan view of an article manipulation system accordingto another embodiment of the invention; and

[0036]FIG. 19 is a plan view of an article manipulation system accordingto yet another embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0037] The present invention will now be described with reference to theaccompanying drawings wherein the reference numerals in the followingwritten description correspond to like-numbered elements in theaccompanying drawings. An article manipulation system 20 according to afirst embodiment of the present invention is depicted in FIGS. 1 and 1A.Article manipulation system 20 moves articles in a direction ofconveyance indicated by arrow 22. Article manipulation system 20includes a feed conveyor 24, a gapper 26, a transition conveyor 28, adistributed manipulation bed 30, and a downstream conveyor 32. Articlemanipulation system 20 further includes one or more article sensors. Inthe illustrated embodiment, a plurality of video cameras 34 and a photosensor array 36 are used. However, other configurations of articlesensors may be used. By way of example, a plurality of parallel photosensor arrays 36 may be spaced along manipulation bed 30 between groupsof individual conveyors 42. Alternatively, other types of overhead imagecapture devices may be used in lieu of cameras 34 to detect shapes ofarticles below.

[0038] In operation, articles 38 travel from feed conveyor 24 ontogapper 26. Gapper 26 enlarges the gaps between articles 38 in at least alateral direction (i.e. in a direction transverse to the direction ofconveyance 22). After passing over gapper 26, articles 38 move ontotransition conveyor 28. The position, size, and orientation of thearticles 38 is detected by photo sensor array 36 and/or video cameras34. This information is fed to a controller 40 which processes thisinformation and controls the speed of the individual conveyors that makeup manipulation bed 30. Controller 40 controls the operation ofmanipulation bed 30 in such a way that articles 38 exit manipulation bed30 one at a time with a desired gap between the articles. Statedalternatively, manipulation bed 30 manipulates articles 38 into a singlestream of articles. As will be discussed more herein, controller 40 canbe optionally programmed to manipulate articles into a dual stream ofexiting articles, such as will be described in more detail with respectto the embodiment depicted in FIGS. 11-17.

[0039] Manipulation bed 30 is made up of a number of individualconveyors 42. In the embodiments of FIGS. 1 and 1A, conveyors 42 arebelt conveyors. It will, of course, be understood that other types ofconveyors 42 can be used within the scope of the present invention, suchas those employing steered or non-steered wheels, rollers, or othertypes of conveying structures. As illustrated in FIGS. 2A and 2B, eachconveyor 42 of a conveyor unit 41 includes a belt 44 that is wrappedaround two or more idler rollers 46 that are generally aligned in ahorizontal plane. Belt 44 is also wrapped around a drive roller 48 thatmay be positioned underneath idler rollers 46. The arrangement andposition of motorized rollers 48 may be like that depicted in FIG. 1A,or, alternatively, like that depicted in FIGS. 2A and 2B.

[0040] In FIGS. 2A and 2B, the position of each drive roller 48 isalternated between a forward position, illustrated in one of the FIGS.2A and 2B, and a rearward position, illustrated in the other of theFIGS. 2A and 2B, for each adjacent conveyor 42. This provides additionalspace for the drive rollers 48, as well as their associated motors 49,and any control wires and/or other structures. Each of the belts or FIG.2A further include a tensioning roller 51 that is in operative contactwith the associated belt. Tensioning rollers 51 are each biased towardtheir associated belt by a spring 51 a operating on an eccentric 51 bwhich is operative to move the shaft which rotatably supports thetensioning roller. Spring 51 a and eccentric 51 b are located opposite asupport plate 43 from the associated tensioning roller. Tensioningrollers 51 maintain a constant amount of tension in the belts 44 due tothe bias placed on tensioning rollers 51. Preferably, although notnecessarily, tensioning rollers 51 are not aligned in a directiontransverse to the direction of conveyance. This provides more space forpositioning supporting structure underneath the top surface of belts 44.

[0041] As an alternative to the belt arrangement depicted in FIGS. 1A,2A and 2B, conveyors 42 could be constructed in a wide variety ofdifferent manners. For example, one of end rollers 46 could be replacedwith a drive roller 48 such that each conveyor 42 only had two rollers.As another alternative, conveyors 42 could be made of four rollers, witheach roller at the vertex of a square or rectangle, when viewed from theside. As yet another alternative, conveyors 42 could include a number ofsupport rollers underneath belt 44 generally in the horizontal plane ofconveyance. Conveyors 42 could also be constructed without a belt 44. Asone example, conveyors 42 could be made of one drive roller 48 connectedby one or more O-rings to a series of adjacent rollers. Conveyors 42could also be constructed in some of the manners described in PCT PatentApplication Serial No. PCT/US01/13556 (Publication No. WO 01/83339), thedisclosure of which is hereby incorporated herein in its entirety.Rollers 46 and 48 may be supported by support beams 50 a and b or may besupported in any other conventional manner.

[0042] Each drive roller 48 is in communication with controller 40 via acommunication line 52. Communication line 52 may be a singlecommunication bus that is connected to each drive roller 48, or it maybe a number of individual communication buses, each of which isconnected to some of the drive rollers 48. As yet another alternative,communication line 52 could comprise separate communication lines fromcontroller 40 to each and every drive roller 48. As will be discussedmore below, controller 40 sends speed control commands overcommunication line 52 to each of drive rollers 48 to thereby control thespeed at which conveyors 42 convey products in the direction ofconveyance 22. Communication line 52 should allow messages communicatedthereover to be transmitted quickly, such as within a few milliseconds,although greater communication times may be used. Controller 40 may alsoinclude additional communications lines (not shown) for communicatingwith other components of the overall material handling system. Thus, ifnot enough articles are being supplied to conveyor 32, controller 40 canincrease its manipulation rate. Alternatively, it can slow down itsmanipulation rate where the downstream conveyors are not processing thearticles quickly enough. Controller 40 preferably, although notnecessarily, controls the speed of conveyors 28 and 32, in addition toconveyors 42 of manipulation bed 30.

[0043] Conveyors 42 of manipulation bed 30 are arranged in an array ormatrix type of arrangement. Stated alternatively, manipulation bed 30 ismade up of a plurality of columns or groups of conveyors 42 identifiedin FIG. 1 by the capital letters A-H. Each of these conveyor groupsextends in a direction generally transverse to the direction ofconveyance 22. Manipulation bed 30 also includes a plurality of conveyorrows identified in FIG. 1 by the lower case letters a-k. In theembodiment illustrated in FIG. 1, there are eight groups (columns) ofconveyors and eleven rows of conveyors 42. Manipulation bed 30 thereforeis made up of 88 individual conveyors 42. Each of these 88 conveyors 42includes a drive roller 48 that has a unique address for communicationwith controller 40. The speed of each individual conveyor 42 cantherefore be individually controlled.

[0044] It will be understood that manipulation bed 30 can includedifferent numbers of groups and rows of conveyors 42. In other words,manipulation bed 30 may include more or less than eight transversegroups of conveyors 42. Likewise, manipulation bed 30 may include feweror more than eleven rows of conveyors 42. The width of each conveyorbelt 44 may range from 10 to 15 centimeters, although widths outside ofthese ranges can also be used. The length of each conveyor 42 may alsovary from 30 to 100 centimeters, although other lengths can also be usedoutside of this range. Further, it is not necessary that the size ofconveyors 42 be uniform throughout manipulation bed 30. For example, inthe embodiment depicted in FIG. 3, the three downstream-most conveyorgroups have a length that is longer than the four upstream-mosttransverse conveyor groups. Other variations are also possible in thesize and shape of conveyors 42.

[0045] Gapper 26 is an optional component that may be utilized toincrease the gaps between articles. The gaps may be increased in adirection transverse to the direction of conveyance 22, a lateraldirection, or both. Increasing this gap will help video cameras 34and/or photo sensor array 36 to distinguish the boundaries of individualarticles 38. Gapper 26, in one embodiment, may include a number ofindividual belt conveyors 54. Each belt conveyor 54 is arranged at anangle with respect to the direction of conveyance 22. The magnitude ofthis angle increases from the center of gapper 26 towards its outeredges. Thus, in FIG. 1 belt conveyor 54D is angled slightly outwardlyfrom the center of gapper 26. Belt conveyor 54C is angled outwardly to agreater extent. Belt 54B is angled outwardly even more and belt 54A isangled outwardly to the greatest extent. Belts 54E-H are shown withangles that are mirror images of the angles of belts 54A-D. As articles38 travel over gapper 26, the angled nature of belt conveyors 54 exertsa transverse force on articles 38. This transverse force tends to createtransverse gaps between the articles, or increase any pre-existingtransverse gaps.

[0046] In order to ensure that a sufficient longitudinal gap existsbetween articles 38 so that video cameras 34 and/or sensor array 36 candistinguish between individual articles, gapper 26 may operate at ahigher longitudinal speed than feed conveyor 24. This higherlongitudinal speed will cause articles traveling from feed conveyor 24onto gapper 26 to have their longitudinal gaps increase. The combinationof feed conveyor 24 and the increased longitudinal speed of gapper 26ensures that articles 38 will be sufficiently separated in both thelateral and longitudinal directions from each other so that they can beproperly detected and processed by sensor array 36 and/or video cameras34. The construction of gapper 26 may vary substantially from thatdepicted herein. For example, alternative constructions using wheels orother non-belt conveying means can be used.

[0047] Transition conveyor 28 may include a single belt 56, or it may beconstructed with multiple belts, such as is illustrated in FIGS. 1-2. Asillustrated, transition conveyor 28 includes two belts 56 that are eachwrapped around a pair of end rollers 58. One of each pair of end rollers58 may be a powered roller which powers the movement of belt 56 in thedirection of conveyance 22. Transition conveyor 28 may alternatively bemade up of a number of additional belts 56, such as is illustrated inthe embodiment depicted in FIG. 3. By using multiple smaller belts 56,rather than one or a few large belts 56, the cost of manufacturingtransition conveyor 28 may be decreased. Transition conveyor 28 is anoptional component and may be omitted, especially in articlemanipulation systems in which no photo-sensor array, such asphoto-sensor array 36, is used.

[0048] Photo sensor array 36 is an optional sensor that, if used, ispreferably placed approximately in the middle of transition conveyor 28.Array 36 should be positioned far enough downstream of gapper 26 suchthat any residual sliding or rotating of articles that may have beencaused by gapper 26 has stopped. The position of the articles detectedby array 36 will therefore not unknowingly change downstream of array36. Photo sensor array 36 consists of a plurality of individual photosensors that are arranged to detect light, or other electromagneticenergy, that is emitted downwardly onto the surface of transitionconveyor 28 and array 36. This light may be fluorescent light that isemitted from a fluorescent light bulb (not shown) positioned above array36 at a sufficient height to allow articles 38 to travel underneath thelight bulb while on transition conveyor 28. Photo sensor array 36includes sensors for detecting the light energy. Because the light, orother energy, will be obscured by articles 38 traveling over array 36,photo sensor array 36 can distinguish between articles 38 and an emptyspace on transition conveyor 28. Photo sensor array 36 preferably,although not necessarily, comprises an array of sensors that are closelypacked together and extend in a transverse direction. The individualsensors of array 36 may be positioned within five millimeters or less ofeach other, although other spacing may be used. The sensor array 36 maybe a conventional product such as is manufactured by Kore Computing ofComstock Park, Mich. or SICK, Inc. of Bloomington, Minn. The outputs ofeach sensor in array 36 are preferably scanned multiple times per secondwith sufficient speed to allow the size, orientation, and position ofarticles 38 to be detected as they pass above array 36. This informationis passed from array 36 to controller 40 by way of a communications line60. Controller 40 uses this information, along with information fromvideo cameras 34 if so equipped, to determine which will be the nextarticle to be manipulated, whether it will need to be rotated, and tomake other determinations as will be discussed in more detail below.

[0049] In the embodiments illustrated in FIGS. 1 and 1A, there are threevideo cameras 34 a-c. It will be understood by those skilled in the artthat a different number of video cameras 34 can be used to practice thepresent invention. As previously disclosed, other article sensors, suchas other types of overhead article shape sensors or additional photosensor arrays spaced along the bed in the direction of article flow, maybe used in the alternative. Video cameras 34 a-c are positioned abovemanipulation bed 30 and transition conveyor 28. Video cameras 34 a-cthus detect the movement of articles 38 on transition conveyor 28 andmanipulation bed 30. Further, video cameras 34 a-c determine theposition and/or shape of each article 38 with sufficient accuracy toallow controller 40 to properly manipulate articles on manipulation bed30. Video cameras 34 a-c communicate with controller 40 over acommunications line 62. Video cameras 34 a-c may be used in conjunctionwith photo-array 36, or they may be used without photo-array 36.Alternatively, the article manipulation system may use only aphoto-array 36 without any video cameras 34.

[0050] Controller 40, which may be a conventional programmable logiccontroller (PLC) a personal computer, or any other type of computer,receives and processes the information from video cameras 34 a-c and/orphoto sensor array 36. Controller 40 includes conventional video imageprocessing software that processes the information received from videocameras 34 a-c. This software allows controller 40 to know preciselywhere each article 38 is positioned on either transition conveyor 28 ormanipulation bed 30. In particular, when articles 38 are positioned onmanipulation bed 30, the output from video cameras 34 a-c allowscontroller 40 to determine which specific conveyors 42 are underneatheach of the articles 38 on manipulation bed 30. Controller 40 then sendsappropriate speed commands over communications line 52 to control thespeed of individual conveyors 42 to effectuate manipulation of article38.

[0051] A diverter/merge conveyor 64 may be positioned adjacent thedownstream end of manipulation bed 30. Diverter/merge conveyor 64 may beused to perform several different functions, depending upon the desiredapplication. In one application, diverter/merge conveyor 64 simplydirects the incoming articles from manipulation bed 30 toward agenerally uniform position on conveyor 64 with respect to its side 66 aand b. This is a useful operation where the conveyor downstream ofconveyor 64 has a narrower width than that of conveyor 64. In order toensure articles exiting conveyor 64 will be aligned with this narrowerwidth, conveyor 64 steers the articles traveling thereon so that theywill be aligned with the downstream conveyor.

[0052] In an alternative application, diverter/merge conveyor 64 may beused to steer articles traveling thereon to two or more downstreamconveyors, each of which may, in turn, lead to a separate conventionalsortation apparatus. In the embodiment depicted in FIG. 3A,diverter/merge conveyor 64 is a conventional steered wheel conveyor. Asillustrated in FIG. 3A, conveyor 64 includes a plurality of individuallysteered wheels 68. Each wheel 68 rotates about a horizontal axis. Theorientation of this horizontal axis can be changed between anorientation parallel to the direction of conveyance 22 to a horizontaldirection that is skew to this. The changing of these horizontal axescan be accomplished in a conventional manner through the use ofactuators 70, or other devices. Typically, each column of wheels 68 thatextends from side 66 a-b are controlled in unison. The individualcolumns can be controlled independently from other columns, if desired.The control of conveyor 64 may be carried out by a local controller thatis part of conveyor 64, or it may be controlled by controller 40. Therotation of wheels 68 exerts a force against articles traveling onconveyor 64. The direction of this force is dependent upon thehorizontal orientation of the horizontal axes of the wheels 68. Byappropriately changing the orientation of these horizontal axes, theside-to-side position of articles traveling on conveyor 64 can bealtered as desired.

[0053] Controller 40 controls the manipulation of articles 38 that takesplace on manipulation bed 30. Controller 40 can be programmed tomanipulate articles in a variety of different manners. A first methodfor manipulating articles is depicted in FIGS. 4-10. A second method ofmanipulating articles is depicted in FIGS. 12-17. In the first method,articles traveling on manipulation bed 30 may be rotated so that theirlongitudinal axis is closer to being parallel to the direction ofconveyance. Regardless of whether articles are rotated or not, thisfirst method of control causes the articles to exit one at a time fromthe downstream end of manipulation bed 30. In the second manner ofmanipulation depicted in FIGS. 12-17, article rotation may or may not beincluded as part of the programming. Regardless of whether rotation isincluded as part of the programming of controller 40, the second methodinvolves allowing articles to simultaneously exit the downstream end ofmanipulation bed 30 provided that the articles are sufficiently spacedapart laterally. These two methods will be described in more detailbelow.

[0054] Referring now to FIG. 4, a plurality of articles 38 are showninitially positioned on transition conveyor 28. Articles 38 have beenindividually identified by capital letters A-G. At the moment in timedepicted in FIG. 4, video cameras 34 and/or photo sensor array 36 haveprovided controller 40 with sufficient information for it to determinethe locations of articles A-G. Controller 40 selects the downstream-mostarticle that can be advanced without colliding with an adjacent article.In the illustration of FIG. 4, article B has a corner that is thefurthest downstream of any other part of the illustrated articles.However, if article B were to be advanced in the direction ofconveyance, it would collide with article A. Therefore, controller 40selects article A as the first article to be manipulated. Controller 40therefore determines which row of conveyors 42 will be positioned underarticle A as it travels over manipulation bed 30.

[0055] The individual conveyors 42 of manipulation bed 30 are generallycontrolled to operate at one of two different speeds. As will bediscussed more below, when rotation of articles is desired, other speedsmay be used other than these two different speeds. The first speed isillustrated in FIG. 4 as V_(u) and refers to the velocity at theupstream end of manipulation bed 30. Speed V_(u) may also be thevelocity of transition conveyor 28. The other speed is illustrated inFIG. 4 as V_(d), and refers to the downstream velocity of manipulationbed 30. Speed V_(d) may also be the speed of downstream conveyor 32. Aboundary line 72 separates those conveyors 42 that are operating atspeeds V_(d) from those operating at the speed V_(u). The conveyorsoperating at speeds V_(d) are also shaded in FIGS. 4-10 for greaterclarity. Speed V_(d) is greater than speed V_(u). Therefore, articlestraveling on conveyors 42 operating at speed V_(d) will separatethemselves from other articles on conveyors 42 traveling at speed V_(u).

[0056] It will be understood that controller 40 may control the speedsof individual conveyors 42 so that articles transitioning acrossboundary 72 from speed Vu to speed V_(d) will have their instantaneousaccelerations reduced or minimized. In other words, a conveyor 42 thatis to operate at speed V_(d), and that is downstream of an adjacentconveyor traveling at speed V_(u), may initially have its speed set tomatch, or come close to, the speed V_(u) of the adjacent upstreamconveyor. After the article has transitioned onto the downstreamconveyor 42, its speed is increased to that of V_(d). In this manner,article slippage on the conveyor belts, noise from this slippage, andwear on the belts is reduced. Conveyor belts 42 therefore may beoperable at two or more non-zero speeds and may be operable atessentially infinitely variable speeds. The shaded areas in theaccompanying drawings representing conveyors 42 operating at speedsV_(d) are thus somewhat generalized to illustrate the underlying controllogic used by controller 40. Individual belts within the shaded areasmay operate at speeds other than Vd, particularly those belts involvedin transitioning an article across boundary line 72. Unoccupied beltsdownstream of those operating at V_(d) also may not operate at this samespeed until the article traveling at speed Vd is actually delivered tothese unoccupied belts.

[0057] Controller 40 operates to alter boundary line 72 as articles 38travel over manipulation bed 30 such that articles are manipulated. Withthe exception of the rotation of articles, the algorithms thatcontroller 40 follows in altering the position of boundary line 72 inFIGS. 4-10 may be the same as those disclosed in International PatentApplication Serial No. PCT/US01/13556, the disclosure of which is herebyincorporated herein by reference.

[0058] As article A transitions from transition conveyor 28 tomanipulation bed 30 in FIG. 4, the speed of article A will increaserelative to the other articles at the moment that article A issufficiently on manipulation bed 30 to be controlled by the conveyors 42underneath it. The longitudinal space between article A and the otherarticles will therefore begin to increase after article A's speedtransitions from that of V_(u) to V_(d). At the moment in timeillustrated by FIG. 5, the individual conveyors 42 that are underneatharticle A are conveyors 42Af and 42Ag. A small portion of article B alsooverlies conveyor 42Af. Because this portion is so small relative to thesize of article B, controller 40 determines that the operation ofconveyor 42Af at speed V_(d) will not affect the position or orientationof article B.

[0059] If article B in FIG. 5 extended further on to conveyor 42Af, thencontroller 40 would only run conveyors 42Af and Ag at speed V_(d) untilarticle B arrived at either or both of these conveyors. At that momentin time, controller 40 would decrease the speed of these two conveyorsto V_(u). The longitudinal gap between article A and article B wouldtherefore only be increased for the time during which article A wastraveling at speed V_(d) while article B was traveling at speed V_(u).If more longitudinal gap were desired between articles A and B than wascreated by operating conveyors 42Af and Ag at speed V_(d), an increasedlongitudinal gap could be created by operating conveyors 42Bf and Bg atspeed V_(d) while article B had not entered onto any of these conveyors.Similar longitudinal gaps between articles A and B could be createdusing conveyors 42Cf and Cg, as well as the conveyors in rows f and gand columns D, E, F, and G.

[0060]FIG. 6 illustrates a moment in time subsequent to that illustratedin FIG. 5. At this moment in time, controller 40 has changed the speedof conveyors Af and Ag back to that of V_(u). Controller 40 hasdetermined that the next article to be manipulated will be article B. Byreturning conveyors 42Af and Ag to speed V_(u), the relative position ofarticle D with respect to the other articles, such as article B will notbe altered. The information that controller 40 receives from videocameras 34 a-c and photo sensor 36 indicates that article A has a skeworientation relative to the sides of 74A and B of manipulation bed 30.Video cameras 34 and sensor array 36 provide sufficient information tocontroller 40 for it to determine this angular orientation with respectto side 74. If this angular orientation exceeds a predetermined value,controller 40 determines that the article should be rotated. The articleis then rotated so that this angle is decreased. This rotation ofarticles helps the downstream processing of articles on the conveyingsystem.

[0061] In general, controller 40 may be programmed to rotate allarticles whose longitudinal orientation is greater than +/−15° withrespect to the direction of conveyance. Other thresholds may be chosen.For square articles greater than a given size, such as 250 mm×250 mm,controller 40 may be programmed to rotate these articles so that one ofthe sides of the article is less skew with respect to the direction ofconveyance. For square articles smaller than this given size, controller40 may be programmed to not rotate the articles, regardless of theirdegree of skew. Oblong or irregularly shaped articles may be processedwith or without rotation, depending on their aspect ratio. If the aspectratio exceeds a given threshold, then rotation would more likely becarried out. Where the aspect ratio does not exceed a given threshold,no rotation would be carried out.

[0062] In the illustrated embodiment, controller 40 determines thatarticle A has such a skew orientation that it will be rotated.Controller 40 will rotate article A in a clockwise direction indicatedby arrow 76 in FIG. 6. This rotation is accomplished by increasing thespeed of conveyor 42Bf relative to that of conveyor 42Bg. Controlledspeed differences between the conveyors in rows f and g that underliearticle A are maintained in each conveyor column until rotation hastaken place. Therefore, as illustrated in FIG. 7, conveyor 42Cf and Cgwill operate with a speed difference, for at least an initial period oftime. In FIG. 7, conveyor 42Cf is operating at a speed V_(d)+K. Conveyor42Cg is operating at a speed V_(d)−K. This difference is speed causesarticle A to rotate such that its sides become less skewed with respectto sides 74 a and b of manipulation bed 30. The precise value of thevariable K can be varied as desired. In order to more quickly rotate anarticle, the value K should be higher, as would be known by one withordinary skill in the art. The value of K may vary for each individualarticle, depending on the degree of skewness of the article, the size ofthe article, and other factors. The value of K may also vary withrespect to time during the rotation of a given article. This timevariation may include a gradual ramping up to a peak value of K,followed by a gradual descending back to a zero value during rotation sothat instantaneous accelerations of the article are reduced. Other typesof time-varying changes to the value of K may also be implemented.Controller 40 may be programmed to rotate articles generally about theircenter position. Video cameras 34 can be used to monitor the actualarticle rotation to provide feedback to controller 40 during therotation process. This feedback is used by controller 40 to control therotation process more accurately.

[0063] As illustrated in FIG. 8, the speed of the conveyors 42underneath article A are reset to V_(d) after the rotation of thearticle is complete. Article A will then continue to travel downmanipulation bed at V_(d). The speed of the conveyors under article Bwill be increased to that of V_(d) when a desired longitudinal gap hasbeen achieved between articles A and B. This gap may be set anywherefrom zero to whatever spacing is desired for articles in a particularapplication. For articles that will not be rotated, the gap is thelongitudinal distance between the upstream end of the leading articleand the downstream end of the trailing article. For situations in whichone or more articles will be rotated, the gap is the longitudinaldistance, after rotation, between the upstream end of the leadingarticle and the downstream end of the trailing article. As illustratedin FIG. 8, the desired gap is less than that between the upstream end ofarticle A and the downstream end of article B because controller 40 hasdetermined that article B will be rotated. The desired gap is thereforethe longitudinal separation between articles A and B that will bepresent after article B has been rotated. Controller 40 computes thisgap and may use feedback from cameras 34 to verify the rotation of thearticles. The size of the desired gap can be dynamically changed bycontroller 40. Once this desired gap has been achieved, conveyors 42 inrows b-e will be set to speed V_(d) for conveyor columns B-F. Article Bwill therefore begin to longitudinally separate from the other articlestraveling at speed V_(u).

[0064] As illustrated in FIG. 9, the rotation of article B is carriedout in a similar manner to that of article A. Specifically, the speed ofthe conveyors in rows b and c underneath article B are increasedrelative to the speed of conveyors 42 in rows d and e. As illustrated inFIG. 9, conveyors 42 Db and Eb are operating at a speed V_(d)+L.Conveyors 42Dc and 42Ec are set at a speed Vd+K. Conveyors 42Dd and Edare set at a speed V_(d)−K. Conveyors 42De and Ee are set at a speedV_(d)−L. These speeds K and L may be set as proportional to the lateraldistance away from the point of rotation on article B. Thus, thevariable L will have a greater value than the variable K. The value ofL, like the value of K, may vary between articles and it may vary withtime over the course of rotating a given article. The varying speeds ofthe conveyors underlining article B will thus cause article B to rotatein a clockwise direction. After rotation, it will have the desiredlongitudinal gap between itself and article A.

[0065] As is also illustrated in FIG. 9, controller 40 will increase thespeed of the conveyors underneath article C when a desired gap isobtained between article B (after rotation) and article C. Becausearticle C will not be rotated, the conveyor 42 underneath article C willsimply be increased to speed V_(d). Once article C has advanced downmanipulation bed 30 such that a desired gap is obtained between articlesC and D, the conveyors 42 underlying article D will have their speedincreased to that of V_(d) by controller 40, as is illustrated in FIG.10. Controller 40 will continue to increase the speed of the underlyingconveyors of each article as desired gaps are obtained. Thus, controller40 will increase the speeds of the conveyors 42 underlying article Eafter a desired gap is obtained. Because article E will be rotated, thisdesired gap will be the gap created after rotation. Controller 40 willcontinue to operate in a similar fashion for articles F and G, and allsubsequent articles.

[0066] While the operation of manipulation bed 30 and controller 40 hasbeen illustrated with respect to only seven articles, it will beunderstood that manipulation bed 30 and controller 40 may operatesubstantially continuously. Alternatively, the operation of manipulationbed 30 may be a batch type of operation. As illustrated in FIG. 10,article A has been manipulated onto downstream conveyor 32. At latermoments in time, articles B, C, and D, as well as the rest of thearticles will arrive at downstream conveyor 32 in a manipulated fashion.As described previously, downstream conveyor 32 may be constructed toalter the lateral position of the manipulated articles with respect tosides 66 a and b.

[0067]FIG. 11 illustrates an alternative embodiment of articlemanipulation system 20′ according to another aspect of the presentinvention. Article manipulation system 20′ differs from that of articlemanipulation system 20 in that a pair of branch conveyors 78 a and b arepositioned downstream of downstream conveyor 32. Articles exitingdownstream conveyor 32 will therefore travel down one of branch conveyor78 a or 78 b. Article manipulation system 20′ includes a feed conveyor24, a gapper 26, a transition conveyor 28, a manipulation bed 30, and adownstream conveyor 32. Further, although not illustrated in FIG. 11, itincludes video cameras 34 and/or a photo sensor array 36 (also notillustrated). Transition conveyor 28 may be made up of a number ofseparate belts in order to minimize the costs of manufacturingtransition conveyor 28. The operation of article manipulation system 20′is illustrated in FIGS. 12-17, which are described in more detail below.

[0068] As a general matter, manipulation bed 30 of article manipulationsystem 20′ operates generally in a similar manner as has been previouslydescribed with respect to article manipulation system 20. Articlemanipulation system 20′ differs from article manipulation system 20 inthat article manipulation system 20′ includes an imaginary dividing line80. Imaginary dividing line 80 is located at a lateral position withrespect to sides 74 a and b of manipulation bed 30 that is collinearwith the separation line between branch conveyor 78 a and b. Controller40 is programmed to allow multiple articles to exit from manipulationbed 30 at the same time in those instances where the multiple articlesare on opposite sides of dividing line 80, or where the articles can beseparated by conveyor 32 so as to travel down each of conveyors 78 a andb. Thus, article manipulation system 20′ manipulates articles, wherepossible, into two streams of articles. This is described in more detailbelow.

[0069] Controller 40 determines that article A will be the first articleto be manipulated. This determination is made using the same criteria asdescribed above with respect to article manipulation system 20.Accordingly, controller 40 increases the speed of those individualconveyors 42 that are in rows f and g to that of V_(d). The conveyors inthese two rows are the conveyors that are laterally in line with articleA. Therefore, when article A enters onto manipulation bed 30, its speedrelative to the other articles will increase, and therefore itslongitudinal separation. As illustrated in FIGS. 12 and 13, article Aoverlies dividing line 80. Thus, a portion of article A lies abovedividing line 80 (toward side 74 a) and a portion of article A liesbelow dividing line 80 (toward side 74 b). Controller 40 thereforedetermines that article A will be manipulated by itself; that is withoutsimultaneously manipulating any other article. Controller 40 of articlemanipulation system 20′ is programmed to determine whether the nextarticle to be manipulated is either fully above or below dividing line80. If controller 40 of article manipulation system 20′ is furtheradapted to rotate articles, then the determination of whether an articleis below or above dividing line 80 is made with respect to the article'spost-rotation position.

[0070] As illustrated in FIG. 14, the longitudinal separation of articleA from the other articles will increase. Controller 40 reduces the speedof conveyors 42Af and Ag after article A has exited from theseconveyors. This reduction in speed back to speed V_(u) prevents articleD from having its position and/or orientation changed with respect tothe other articles traveling at speed V_(u). Controller 40 determinesthat the next article to be manipulated is article B. Controller 40determines that article B is fully above dividing line 80. Therefore,controller 40 next determines if article B has any overlapping alignmentin a transverse direction with another article (FIG. 15). Thisdetermination is made by extending the trailing and leading edges ofarticle B perpendicularly toward one of sides 74 a and b. The trailingand leading edges of article C are also extended toward the same side.To the extent the area between the trailing and leading edges of eachrespective package overlaps, controller 40 concludes that there isoverlapping alignment in a direction transverse to the direction ofconveyance. In the example illustrated in FIG. 15, controller 40determines that articles B and C have overlapping transverse alignment.Controller 40 therefore next determines whether article C is positionedon an opposite side of dividing line 80 as article B. In the illustratedcase, it is. Therefore, controller 40 determines that articles B and Ccan be simultaneously advanced toward the downstream end of manipulationbed 30. Articles B and C will thus exit manipulation bed 30 at acoincident moment in time. Because they are positioned on opposite sidesof the dividing line 80, article B will end up proceeding down branchconveyor 78 a, while article C will eventually move down branch conveyor78 b. By simultaneously advancing articles B and C together,manipulation bed 30 can increase its throughput. If article C had notbeen on an opposite side of dividing line 80, then controller 40 wouldhave changed the speeds of the conveyors under article B such that itwould have advanced ahead of article C.

[0071] As illustrated in FIG. 16, the individual conveyors 42 underlyingarticle D will have their speed increased to that of V_(d) when adesired gap is created between either article B or article C. Controller40 will determine which of articles B or C to use as a reference for thegap between it and article D on the basis of which branch conveyor 78article D will be traveling down. Specifically, because a majority ofarticle D is positioned below dividing line 80, downstream conveyor 32will likely divert article C down branch conveyor 78 b. Therefore,controller 40 will wait until the gap between articles C and D reaches adesired gap before increasing the speed of the conveyors 42 underneatharticle D to that of V_(d). Controller 40 therefore determines thedesired gap between articles that will successively travel down the samebranch conveyor 78.

[0072] As illustrated in FIG. 17, controller 40 will determine thatarticle E is the next article to be manipulated. Controller 40 willdetermine that article E is completely on one side of dividing line 80.Controller 40 will therefore determine whether article E has anyoverlapping alignment with another article. Because article E doesindeed have overlapping alignment with article F (see FIG. 16),controller 40 will next determine whether article F is completely belowdividing line 80. Because article F is not completely below dividingline 80, articles E and F cannot be manipulated simultaneously. This isbecause divert/merge conveyor 64 does not have the means to separatearticles E and F laterally such that one of them will travel downconveyor 78 a and the other down conveyor 78 b. Therefore, controller 40will increase the speeds of conveyors 42 underneath article E to that ofV_(d). As illustrated in FIG. 17 this will increase the longitudinalspacing between articles E and F. If a divert/merge conveyor 64 is usedthat allows the lateral spacing between articles thereon to becontrolled, then it would be possible to manipulate articles E and Fsimultaneously. Conveyor 64 would separate these articles so that theyexited conveyor 64 on opposite sides of dividing line 80, therebydirecting them to opposite branch conveyors 78 a and b.

[0073] Controller 40 next determines that article F is completely to oneside of dividing line 80 and that it has overlapping transversealignment with respect to article G. Furthermore, controller 40determines that article G is completely to the other side of dividingline 80. Therefore, controller 40 will simultaneously advance articles Fand G so that they can be manipulated together, in the same manner thatarticles B and C were manipulated.

[0074] Manipulation bed 30 of article manipulation system 20′ may alsooperate in a continuous fashion or a batch fashion, just as manipulationbed 30 of article manipulation system 20. As has been noted previously,controller 40 of article manipulation system 20′ may optionally includeprogramming that allows articles to be rotated in a manner describedwith respect to FIGS. 4-10. When controller 40 is programmed in thisway, controller 40 makes all of its determinations with respect todividing line 80 based on the post-rotational position of articles. Inother words, controller 40 determines what positions articles will be inafter they are rotated. These post-rotation positions are then used todetermine whether an article is completely on one side or another ofdividing line 80 as well as whether or not it has any transversealignment with another article.

[0075] The gaps between articles exiting manipulation bed 30 of articlemanipulation system 20′ may be dynamically controlled by controller 40.Controller 40 may alter these gaps based on information it receives fromother components in the overall conveyor or material handling system.Alternatively, the gaps may be adjusted by an operator inputting thisinformation into controller 40. In article manipulation system 20′, thedesired gaps are determined with respect to articles that will traveldown the same branch conveyor 78 a or b. Thus, a pair of articles mayexit bed 30 with less than the desired longitudinal gap between the twoarticles if they are to be sent down opposite ones of conveyors 78 a andb. In such a case, it is the longitudinal gap between each article andthe downstream article on the same destination conveyor 78 a or b thatis controlled, not the longitudinal gap between each article in thepair.

[0076]FIGS. 18 and 19 depict two alternative implementations of anarticle manipulation system according to the present invention. In theembodiment of FIG. 18, the article manipulation system 20″ includes abulk conveyor 24, photo-sensor array 36, transition conveyor 28,manipulation bed 82, merge conveyor 82, and take-away conveyor 84.Article manipulation system 20″ does not include a gapper 26.Photo-sensor array 36 is positioned at an upstream end of transitionconveyor 28, rather than in a center region of conveyor 28. Mergeconveyor 82 may include a merge bar 86 that is angled with respect tothe direction of conveyance. Merge bar 86 causes articles traveling onmerge conveyor 82 that come into contact with it to be pushed toward theside of conveyor 82 that is aligned with take-away conveyor 84. Mergeconveyor 82 thus does not need to use wheels, or other types ofactuators, to merge incoming article streams into exiting articlestreams having a smaller lateral expanse. Article manipulation system20″ may further include a vision processor 88 that is discrete fromcontroller 40. Processor 88 may pre-process the raw signals receivedfrom cameras 34 and/or sensor array 36 before passing the sensedinformation onto controller 40. Processor 88 may include any suitablemicroprocessor and associated hardware components.

[0077] Article manipulation system 20′″ of FIG. 19 includes the samecomponents as article manipulation system 20″, and further includes agapper 26. Photo-sensor array 36 is positioned in the center region oftransition conveyor 28. Article manipulation system 20′″ includes amerge conveyor 82 that may be the same as the merge conveyor 82 ofarticle manipulation system 20″.

[0078] While the present invention has been described in terms ofseveral preferred embodiments depicted in the drawings and discussed inthe above specification, it will be understood by one skilled in the artthat the present invention is not limited to these particularembodiments, but includes any and all such modifications that are withinthe spirit and scope of the present invention as defined in the appendedclaims.

1. A system for manipulating articles generally traveling in a directionof conveyance comprising: a bed comprising a plurality of conveyorgroups, each said conveyor group being generally aligned with each otherin the direction of conveyance and each said conveyor group comprising aplurality of individual conveyors positioned side-by-side in a directiontransverse to the direction of conveyance, said conveyors adapted to atleast partially support articles traveling thereon and to move thearticles in the direction of conveyance; at least one sensor adapted todetermine the position of the articles traveling over said plurality ofconveyor groups; and a controller in communication with said at leastone sensor and said conveyors, said controller adapted to manipulatearticles traveling on said bed by controlling the speed of saidconveyors, said controller further adapted to rotate an articlepositioned on said bed by controlling the speed of selected ones of theconveyors underneath the article such that at least a first one of saidselected ones of said conveyors has a different speed than a second oneof said selected conveyors.
 2. The system of claim 1 wherein saidcontroller is further adapted to cause at least one other article onsaid bed to move in the direction of conveyance while an article isbeing rotated on said bed.
 3. The system of claim 1 wherein saidcontroller is adapted to rotate an article generally about a center ofthe article.
 4. The system of claim 1 wherein the speed of said selectedones of said conveyors is set generally as a function of a distance ofsaid selected ones of said conveyor to a point on the article.
 5. Thesystem of claim 4 wherein said point on the article is an intended pointof rotation of the article.
 6. The system of claim 4 wherein said pointon the article is substantially at a center of gravity of the article.7. The system of claim 1 further including a flow-splitter positionedadjacent to a downstream end of said bed, said flow-splitter adapted tosteer articles exiting said bed to one of a plurality of downstreamconveyors.
 8. The system of claim 7 wherein said flow-splitter comprisesa plurality of powered, steerable wheels that define a conveyingsurface.
 9. The system of claim 1 wherein said controller is furtheradapted to determine if two articles having overlapping alignment in atransverse direction on said bed are on opposite sides of a dividingline extending in the direction of conveyance, said transverse directionextending in a direction transverse to the direction of conveyance, saidcontroller adapted to cause said two articles to exit said bed during atleast one coincident moment in time if said two articles are on oppositesides of said dividing line.
 10. The system of claim 9 wherein saiddividing line is positioned in a center of said bed.
 11. The system ofclaim 1 wherein said controller is further adapted to determine if twoarticles on said bed meet the conditions of: (i) said two articleshaving overlapping alignment in a direction transverse to the directionof conveyance and being on opposite sides of a dividing line extendingin the direction of conveyance; or (ii) one or both of said two articlescan be rotated before exiting said bed such that said two articles willhave overlapping transverse alignment on opposite sides of said dividingline after rotation; said controller adapted to cause said two articlesto exit during at least one coincident moment in time if either ofconditions (i) or (ii) are met.
 12. The system of claim 11 wherein saiddividing line is positioned generally at a center of said bed.
 13. Thesystem of claim 1 wherein said conveyors are belt conveyors.
 14. Thesystem of claim 1 wherein said at least one sensor comprises at leastone video camera positioned above said bed.
 15. The system of claim 1wherein said at least one sensor includes at least one array ofphoto-sensors oriented to emit and detect signals traveling generally ina vertical direction, said signals being obstructed by articlestraveling past said array.
 16. The system of claim 1 further including agapping mechanism positioned upstream of said bed, said gappingmechanism adapted to move articles traveling thereon further apart in adirection transverse to the direction of conveyance.
 17. The system ofclaim 16 further including a transition belt positioned adjacent adownstream end of said gapping mechanism, said transition belt operatingat a speed such that articles traveling from said gapping mechanism tosaid transition belt are moved further apart in a direction parallel tothe direction of conveyance.
 18. The system of claim 1 further includinga transition belt upstream of said bed, said transition beltsubstantially continuously feeding said bed articles to be manipulated.19. The system of claim 1 wherein said controller is adapted to separatea batch of articles.
 20. The system of claim 1 wherein said controlleris adapted to singulate articles.
 21. A method of manipulating articles,comprising: providing a bed having at least one conveying surfaceadapted to move articles in a direction of conveyance from an upstreamend to a downstream end of said bed; providing at least one sensor andusing said at least one sensor to determine the position of any articleson said bed during at least one moment in time; selecting an article onsaid bed to be manipulated; determining whether said selected article isto be rotated; moving said selected article in the direction ofconveyance at a speed generally higher than articles traveling on saidbed that have yet to be manipulated; and if said article is to berotated, rotating the selected article.
 22. The method of claim 21wherein said rotating said selected article includes simultaneouslymoving at least an upstream portion of said conveying surface such thatone or more articles can be received at an upstream end of said bedwhile said article is being rotated.
 23. The method of claim 21 whereinsaid bed comprises a plurality of conveyor groups, each said conveyorgroup being generally aligned with each other in the direction ofconveyance and each said conveyor group comprising a plurality ofindividual conveyors positioned side-by-side in a direction transverseto the direction of conveyance.
 24. The method of claim 23 wherein saidindividual conveyors are belt conveyors.
 25. The method of claim 21further comprising substantially continuously feeding articles to saidbed.
 26. The method of claim 25 further comprising manipulatingarticles.
 27. The method of claim 21 further comprising feeding articlesto said bed in a batch.
 28. The method of claim 27 further comprisingseparating articles from a batch.
 29. The method of claim 21 comprisingrotating the selected article generally about a center of the article.30. The method of claim 21 further comprising determining if twoarticles having overlapping alignment in a transverse direction on saidbed are on opposite sides of a dividing line extending in the directionof conveyance, said transverse direction extending in a directiontransverse to the direction of conveyance; and moving said conveyingsurface such that said two articles exit said bed during at least onecoincident moment in time if said two articles are on opposite sides ofsaid dividing line.
 31. The method of claim 21 further comprisingdetermining if two articles on said bed meet the conditions of: (i) saidtwo articles having overlapping alignment in a direction transverse tothe direction of conveyance and being on opposite sides of a dividingline extending in the direction of conveyance; or (ii) one or both ofsaid two articles can be rotated before exiting said bed such that saidtwo articles will have overlapping transverse alignment and be onopposite sides of said dividing line after rotation; and moving saidconveying surface such that the two articles exit said bed during atleast one coincident moment in time if either of conditions (i) or (ii)are met.
 32. The method of claim 21 wherein said at least one conveyingsurface is made up of a plurality of conveyors and wherein said rotatingthe selected article comprises controlling the speed of selected ones ofsaid conveyors such that at least a first one of said selected ones ofsaid conveyors has a different speed than a second one of said selectedconveyors.
 33. A system for manipulating articles generally traveling ina direction of conveyance comprising: a bed having at least oneconveying surface adapted to move articles in a direction of conveyancefrom an upstream end to a downstream end of said bed; at least onesensor adapted to determine the position of the articles traveling onsaid bed; and a controller in communication with said at least onesensor and said bed, said controller adapted to manipulate articlestraveling on said bed by controlling the speed of said conveyingsurface, said controller further adapted to determine if two articleshaving overlapping alignment in a transverse direction on said bed areon opposite sides of a dividing line extending in the direction ofconveyance, said transverse direction extending in a directiontransverse to the direction of conveyance, said controller adapted tocause the two articles to exit a downstream end of said bed during atleast one coincident moment in time if the two articles are on oppositesides of said dividing line.
 34. The system of claim 33 wherein saiddividing line is positioned in a center of said bed.
 35. The system ofclaim 33 said bed comprises a plurality of conveyor groups, each saidconveyor group being generally aligned with each other in the directionof conveyance and each said conveyor group comprising a plurality ofindividual conveyors positioned side-by-side in a direction transverseto the direction of conveyance.
 36. The system of claim 35 wherein saidindividual conveyors are belt conveyors.
 37. The system of claim 33wherein said at least one sensor comprises at least one video camerapositioned above said bed.
 38. The system of claim 33 further includinga gapping mechanism positioned upstream of said bed, said gappingmechanism adapted to move articles traveling thereon further apart in adirection transverse to the direction of conveyance.
 39. The system ofclaim 38 further including a transition belt positioned adjacent adownstream end of said gapping mechanism, said transition belt operatingat a speed such that articles traveling from said gapping mechanism tosaid transition belt are moved further apart in a direction parallel tothe direction of conveyance.
 40. The system of claim 33 wherein said atleast one sensor includes at least one array of photo-sensors orientedto emit and detect signals traveling generally in a vertical direction,said signals being obstructed by articles traveling past said array. 41.The system of claim 33 wherein said controller is further adapted to:(i) determine if one or both of said two articles can be rotated beforeexiting said bed such that said two articles will have overlappingtransverse alignment and be on opposite sides of said dividing lineafter rotation; and (ii) cause said conveying surface to move such thatthe two articles exit said bed during at least one coincident moment intime if condition (i) is met.
 42. The system of claim 33 wherein saidcontroller is further adapted to be able to rotate an article positionedon said bed by controlling the speed of selected portions of theconveying surface underneath the article such that different portions ofthe conveying surface underneath the article have different speeds. 43.The system of claim 42 wherein said controller is further adapted tocause at least one other article on said bed to move in the direction ofconveyance while an article is being rotated.
 44. The system of claim 33further including a transition belt upstream of said bed, saidtransition belt substantially continuously feeding said bed articles tobe manipulated.
 45. A method of manipulating articles, comprising:providing a bed having at least one conveying surface adapted to movearticles in a direction of conveyance from an upstream end to adownstream end of said bed; providing at least one sensor and using saidsensor to determine the position of any articles on said bed during atleast one moment in time; determining whether two articles on said bedhave overlapping alignment in a transverse direction and whether saidtwo articles are on opposite sides of a dividing line, said transversedirection extending in a direction transverse to the direction ofconveyance, and said dividing line extending in the direction ofconveyance; and if said two articles are on opposite sides of saiddividing line and have overlapping transverse alignment, moving the twoarticles such that they exit a downstream end of said bed during atleast one coincident moment in time.
 46. The method of claim 45 whereinsaid dividing line is positioned in a center of said bed.
 47. The methodof claim 45 wherein said bed comprises a plurality of conveyor groups,each said conveyor group being generally aligned with each other in thedirection of conveyance and each said conveyor group comprising aplurality of individual conveyors positioned side-by-side in a directiontransverse to the direction of conveyance.
 48. The method of claim 47wherein said individual conveyors are belt conveyors.
 49. The method ofclaim 45 further comprising substantially continuously feeding articlesto said bed to be manipulated.
 50. The method of claim 45 furthercomprising: (i) determining if one or both of said two articles can berotated before exiting said bed such that said two articles will haveoverlapping transverse alignment and be on opposite sides of saiddividing line after rotation; and (ii) if condition (i) is met, rotatingone or both of said articles and moving said conveying surface such thatthe two articles exit said bed during at least one coincident moment intime.
 51. The method of claim 45 further including spreading articlesapart in a direction transverse to the direction of conveyance prior tosaid articles entering onto said bed.
 52. A system for manipulatingarticles generally traveling in a direction of conveyance comprising: abed comprising a plurality of conveyor groups, said conveyor group beinggenerally aligned with each other in the direction of conveyance andeach said conveyor group comprising a plurality of individual conveyorspositioned side-by-side in a direction transverse to the direction ofconveyance, said conveyors adapted to at least partially supportarticles traveling thereon and to move the articles in the direction ofconveyance; at least one sensor adapted to determine the position of thearticles traveling over said plurality of conveyor groups; and acontroller in communication with said at least one sensor and saidconveyors, said controller adapted to manipulate articles traveling onsaid bed by controlling the speed of said conveyors, said controllerfurther adapted to be able to control the speed of said conveyors atmore than two different non-zero speeds.
 53. The system of claim 52further including a transition belt upstream of said bed, saidtransition belt substantially continuously feeding said bed articles tobe manipulated.
 54. The system of claim 52 wherein said controller isfurther adapted to be able to rotate an article positioned on said bedby controlling the speed of selected ones of the conveyors underneaththe article such that at least a first one of said selected ones of saidconveyors has a different speed than a second one of said selectedconveyors.
 55. The system of claim 52 wherein said controller is furtheradapted to determine if two articles having overlapping alignment in atransverse direction on said bed are on opposite sides of a dividingline extending in the direction of conveyance, said transverse directionextending in a direction transverse to the direction of conveyance, saidcontroller adapted to cause said two articles to exit a downstream endof said bed during at least one coincident moment in time if said twoarticles are on opposite sides of said dividing line.
 56. An articlemanipulation bed, comprising: a plurality of conveyor groups, saidconveyor groups being generally aligned with each other in a directionof conveyance and each of said conveyor groups comprising a plurality ofconveyor units positioned side-by-side in a direction transverse to thedirection of conveyance; each of said conveyor units comprising a firstconveyor belt reeved at least partially around at least two first idlerrollers, said first conveyor belt adapted to move articles carriedthereon in a direction of conveyance; each of said conveyor unitsfurther comprising a second conveyor belt reeved at least partiallyaround at lest two second idler rollers, said second conveyor beltadapted to move articles carried thereon in said direction ofconveyance, said second conveyor belt being positioned alongside saidfirst conveyor belt; each of said conveyor units further comprising afirst drive roller about which said first conveyor belt is at leastpartially reeved, said first drive roller rotatable about a first axis;and each of said conveyor units further comprising a second drive rollerabout which said second conveyor belt is at least partially reeved, saidsecond drive roller rotatable about a second axis; wherein said firstand second axes are not collinear with respect to each other in adirection transverse to the direction of conveyance.
 57. Themanipulation bed of claim 56 wherein said first drive roller ispositioned forwardly, in said direction of conveyance, of said seconddrive roller.
 58. The manipulation bed of claim 56 wherein each of saidconveyor units further including a first motor attached to said firstdrive roller and a second motor attached to said second drive roller,said first motor extending toward said second conveyor belt in adirection transverse to the direction of conveyance, and said secondmotor extending toward said first conveyor belt in a directiontransverse to the direction of conveyance.
 59. The manipulation bed ofclaim 56 wherein said upstream end rollers of said first and secondconveying belts are aligned with each other in a direction transverse tothe direction of conveyance, and said downstream end rollers of saidfirst and second conveying belts are aligned with each other in adirection transverse to the direction of conveyance.
 60. Themanipulation bed of claim 56 wherein each of said conveyor units furthercomprising a first tensioning roller in contact with said first conveyorbelt and a second tensioning roller in contact with said second conveyorbelt.
 61. The manipulation bed of claim 60 wherein each of said conveyorunits further comprising a first tensioning spring for biasing saidfirst tensioning roller and a second tensioning spring for biasing saidsecond tensioning roller.
 62. The manipulation bed of claim 56 whereineach of said conveying units further comprising a support plate betweensaid first and second conveyor belts for supporting said first andsecond idler rollers and said first and second drive rollers.